/*******************************************************************************************
 * Copyright (c) 2006-2009 Alex Robson, Rob Simmons, Craig Israel, and Rachel Twyford
 *
 * Use of this software in any form requires that you have both 
 * read and agreed to the following terms:
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions: 
 *
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * Redistributions in binary form must reproduce the above copyright notice, 
 * this list of conditions and the following disclaimer in the 
 * documentation and/or other materials provided with the distribution.
 * Neither the name of Nvigorate nor the names of its contributors may 
 * be used to endorse or promote products derived from this software without 
 * specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL ANY CONTRIBUTOR BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ****************************************************************************************/

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Nvigorate.Common.Reflection;
using Nvigorate.Relational.Binding;
using Nvigorate.Relational.Mapping.Index;
using Nvigorate.Relational.Mapping.Interface;
using Nvigorate.Relational.State;

namespace Nvigorate.Relational.Repository
{
    public class QueryBuilderHelper
    {
        //public static IEnumerable<PropertyInfo> GetChildProperties(IRepositoryMapIndex index, Type type)
        //{
        //    return GetRelativePropertyNames(index, type)
        //        .Select(p => Reflector.GetPropertyInfo(type, p, true));
        //}

        //public static IEnumerable<Type> GetChildTypes(IRepositoryMapIndex index, Type type)
        //{
        //    return GetRelativePropertyNames(index, type)
        //        .Select(p => Reflector.GetPropertyInfo(type, p, true))
        //        .Select(p =>
        //            {
        //                return Reflector.IsEnumerable(p.PropertyType) ?
        //                    p.PropertyType.GetGenericArguments().First() :
        //                    p.PropertyType;
                        
        //            })
        //        .Distinct();
        //}

        public static IEnumerable<PropertyInfo> GetChildPropertiesForLazyLoad(Type type)
        {
            return Reflector.GetPropertyInfoList(type)
                .Where(p => (
                                Reflector.HasBaseTypeOf(p.PropertyType, typeof(ITrackState)) ||
                                Reflector.HasBaseTypeOf(
                                    Reflector.GetGenericTypeArgument(type, p.Name) ?? typeof(object),
                                    typeof(ITrackState))
                            ))
                .Concat(Reflector.GetPropertyInfoByAttribute<RelativeAttribute>(type))
                .Distinct()
                .ToList();
        }

        protected static IEnumerable<string> GetRelativePropertyNames(IRepositoryMapIndex index, Type type)
        {
            try
            {
                var map = index.GetMap(type);

                return map
                    .Relationships
                    .Where(r => r.Relationship == Relationship.Parent ||
                                r.Relationship == Relationship.Pair ||
                                r.Relationship == Relationship.Peer)
                    .Select(r => r.RelativeProperty ?? GetDefaultChildPropertyName(type, r.RelativeType))
                    .Where(s => s != null);
                    
            }
            catch (Exception e)
            {
                return new string[] { };
            }
        }

        public static IEnumerable<ITargetRelationship> GetRelatives(IRepositoryMapIndex index, Type type)
        {
            var map = index.GetMap(type);
            return map.Relationships;
        }

        public static string GetDefaultChildPropertyName(Type type, Type childType)
        {
            var propertyInfo = Reflector.GetPropertyInfoList(type)
                .FirstOrDefault(p => (
                                         Reflector.HasBaseTypeOf(p.PropertyType, typeof(ITrackState)) ||
                                         Reflector.HasBaseTypeOf(
                                             Reflector.GetGenericTypeArgument(type, p.Name) ?? typeof(object),
                                             typeof(ITrackState))
                                     ) && 
                                     (
                                         p.PropertyType.Equals(childType) || 
                                         childType.Equals(p.PropertyType.GetGenericArguments().First())
                                     )
                );
            return propertyInfo == null ? null : propertyInfo.Name;
        }
    }
}